A single sharp crystal of transparent Halite, from this most classic of old European salt mines. Historically, the mines were tremendously important for trade and economics, with the profits on mining (and taxes on mining and transport) fueling a huge segment of European economy in the middle ages. The history of the salt mines alone, is the subject of excellent documentaries and books (such as The Story of Salt: The Amazing role of salt in World History by Mark Kurlansky and S. D. Schindler, Published by Puffin Books). The crystal glows like crazy under UV light, as a bonus. This is classic, collectible, and amazing to think about. However, it should not go to Miami or anywhere hot and humid, or it will slowly decay over time. (Halite likes cold, dry places with stable air conditioning and low humidity.)